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Could anyone chime in on why SVS Ultra drivers do so poorly in maximum upper bass SPL? It must be a very inefficient driver, but why throw away so much sensitivity? JTR's Captivator clearly shows you can achieve exceptionally high maximum SPL both down low and up high with a low Mms "high-ish" sensitivity driver. What's the advantage gained with such a low sensitivity driver? They clearly chose to do this to maximize low bass output, but if that's the only reason, it seems to be a rather big sacrifice, especially when looking at what the Cap is capable of.

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I'm sure they slice out any rising response if the driver has it with internal DSP shaping. Had these been passive systems where Ricci could dump a larger amp worth of CEA burst...it might look different.

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Inductance could come into play here, but I'm not sure it does. I've noted already that in sealed systems, mass doesn't do much to response except cut the high end. It improves sensitivity and efficiency down low only slightly. It may also have some slight benefit as far as distortion is concerned.

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Inductance may be a factor on the 16 drivers even with shorting rings in the motor. An 8" coil is a large amount of wire even if it is only a 2 layer or a shallow wind height. The Tymphany driver Kyle linked is the platform they are based on that seems clear, but I'm sure SVS 's version are modified for their specific apps. They do say one is an overhung and the other is underhung for example. It's probable that SVS developed that driver with them as the build house and now Tymphany is offering their own version. A few things pop out off of the Tymphany spec sheet though. The frame OD is 15" even on the spec sheet so I wonder why list it as a 16"? Also the former ID is listed at 7.4" so it seems like a 7.5" coil not 8". Still huge for sure. MMS is listed at 538g on the T driver which is heavy but honestly lighter than I would've imagined with such a large diameter former and coil. Motor efficiency is about 160. 1w/1m sens is rated at 83dB. That's pretty low. The gap height is very large at 36mm and xmax is only listed at 10.5mm. I'd assume that's a very basic coil overhang figure with no adder. That would be very conservative with such a large gap height and 57mm overhung coil wind. Using a calculation that adds 1/3rd gap height to the overhang would put Xmax 22.5mm and assuming I'm correct the coil wouldn't leave the gap completely until 46.5mm one way. I'd expect that driver to exhibit a very broad BL curve with shallow reduction in force as the coil moves away from centered in the gap so it should certainly be capable of a ton of excursion with distortion increasing relatively slowly as excursion increases. Again SVS's units could be substantially different so I'm just speculating most of this off of the T driver data sheet.

Found a cutaway...Looks like they are using a bucking mag up top to get a bit more flux through the gap. Also 2 big aluminum sleeves.

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But on a realistic note: No one is going to purchase SVS's 16" woofer system, pluck the driver, and send it into Ricci to be tested. People may say they are going to but no one will.

And is no one going to chime in on their verbage for their notes on the response plot [red/orange arrows]? I had a lot respect for SVS until I saw their web page for this subwoofer system and the verbage and specifics (technicalities) they used for this subwoofer system. Or am I just "that guy" that is saying what everyone else is thinking but no one is willing to say it?

I hear you. What kind of tests/measurements you are after?

On 13.10.2016 at 7:00 AM, Electrodynamic said:

The 8" coil is for power handling.* Edgewound is a nice touch but 8" diameter does not always indicate higher motor strength.

It is not edgewound coil. It has round wire.

On 13.10.2016 at 5:42 PM, Ricci said:

I was wondering what the frame diameter is on that driver. Could be actually 16" or could be 17".

16"

On 17.12.2016 at 6:27 PM, lukeamdman said:

Eh. You'd get more SPL and better response with two PB-13 Ultras.

Very true. Actually you won't even need two.

On 1.2.2017 at 1:02 AM, lowerFE said:

Could anyone chime in on why SVS Ultra drivers do so poorly in maximum upper bass SPL?

High moving mass, lots of inductance.

On 1.2.2017 at 6:59 PM, Ricci said:

It's probable that SVS developed that driver with them as the build house and now Tymphany is offering their own version. A few things pop out off of the Tymphany spec sheet though. The frame OD is 15" even on the spec sheet so I wonder why list it as a 16"? Also the former ID is listed at 7.4" so it seems like a 7.5" coil not 8".

SVS has their own proprietary basket (+cone and surround) which indeed is 16". Tymphany's own version is 15".

On 2.2.2017 at 7:00 PM, Kyle said:

The Plus/2 was awesome too, I loved that sub.

Old school subs for the win

I also had PB12-Ultra and PB12-Plus/2. Great subs.

On 15.2.2017 at 7:48 PM, andy497 said:

There is so little spider left in that basket compared to the coil, I would think that would severely limit the travel.

SVS has their own proprietary basket (+cone and surround) which indeed is 16". Tymphany's own version is 15".

I also had PB12-Ultra and PB12-Plus/2. Great subs.

That is correct.

Quoting from a full year ago? Please see my comments about this driver in the newer thread. It is a nice driver, just not for those on these forums that are happy to plop subwoofers in 20+ ft^3 tuned low. Apparently small sealed does not go over well (we know this because our 11's and 12's are our lowest selling offerings on the forums). But as to your question about my question of T/S's...a proper T/S parameter spec sheet would be good here at Data-Bass. At the time of my post (a full year ago) SVS didn't post enough T/S parameters to model their driver. They really didn't need to do so as they offer a turn-key product but here on Data-Bass a list of T/S parameters is usually a good starting point.

You can add mass without adding inductance. High moving mass is not always indicative of high inductance. See our HST-11 mkII and HST-12 mkII. High moving mass and very good Le:Re ratio behavior.

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Quoting from a full year ago? Please see my comments about this driver in the newer thread. It is a nice driver, just not for those on these forums that are happy to plop subwoofers in 20+ ft^3 tuned low. Apparently small sealed does not go over well (we know this because our 11's and 12's are our lowest selling offerings on the forums). But as to your question about my question of T/S's...a proper T/S parameter spec sheet would be good here at Data-Bass. At the time of my post (a full year ago) SVS didn't post enough T/S parameters to model their driver. They really didn't need to do so as they offer a turn-key product but here on Data-Bass a list of T/S parameters is usually a good starting point.

You can add mass without adding inductance. High moving mass is not always indicative of high inductance. See our HST-11 mkII and HST-12 mkII. High moving mass and very good Le:Re ratio behavior.

Sorry, I am little late to the party. Could you please point me to the newer thread, I could not find it.

I did not mean that high moving mass would always be an indicative of high inductance, I was just replying to his question.

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This looks like a driver that's good at only one thing: dissipating all the power that is needed for it to make any sound. I reckon the native response of this thing is terribly humped, so they need aggressive DSP just to get a flattish response. What were they thinking?

This thing seems to be optimized to reduce rate of warranty claims. I gather the super stiff suspension helps make it more "abuse tolerant" as well. Perhaps they've decided that customers choose a sub based on the power rating of the amp, and then they run it in the system with the gain knob turned to max.

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Taking a stab at the finished enclosure dimensions after bracing and ports of ~ 7.5 cubes and plugging in the numbers in WinISD, letting it autocalculate the unknowns, the actual power across the coil looks surprisingly low, with a 47 ohm impedance peak in the 40 hz range.

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Taking a stab at the finished enclosure dimensions after bracing and ports of ~ 7.5 cubes and plugging in the numbers in WinISD, letting it autocalculate the unknowns, the actual power across the coil looks surprisingly low, with a 47 ohm impedance peak in the 40 hz range.

It also says 5 kW peak amp power. You can choose to believe them or me.